Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2022 May 23;60(8):1308-1312.
doi: 10.1515/cclm-2022-0263. Print 2022 Jul 26.

Results of a SARS-CoV-2 virus genome detection external quality assessment round focusing on sensitivity of assays and pooling of samples

Christoph Buchta  1 , Jeremy V Camp  2 , Jovana Jovanovic  1 , Elisabeth Puchhammer-Stöckl  2 , Robert Strassl  3 , Mathias M Müller  1 , Andrea Griesmacher  1 , Stephan W Aberle  2 , Irene Görzer  2
Affiliations
Free article

Results of a SARS-CoV-2 virus genome detection external quality assessment round focusing on sensitivity of assays and pooling of samples

Christoph Buchta et al. Clin Chem Lab Med. .
Free article

Abstract

Objectives: Results of earlier external quality assessment (EQA) rounds suggested remarkable differences in the sensitivity of SARS-CoV PCR assays. Although the test systems are intended to detect SARS-CoV-2 in individual samples, screening is often applied to sample pools to increase efficiency and decrease costs. However, it is unknown to what extent these tests actually meet the manufacturer's specifications for sensitivity and how they perform when testing sample pools.

Methods: The sensitivity of assays in routine use was evaluated with a panel of positive samples in a round of a SARS-CoV-2 virus genome detection EQA scheme. The panel consisted of samples at or near the lower limit of detection ("weakly positive"). Laboratories that routinely test sample pools were asked to also analyze the pooled EQA samples according to their usual pool size and dilution method.

Results: All participants could detect a highly positive patient-derived sample (>106 copies/mL). Most (96%) of the test systems could detect at least 1,000 copies/mL, meeting the minimum acceptable benchmark, and many (94%) detected the vRNA in a sample with lower concentration (500 copies/mL). The false negative ratio increased to 16 and 26% for samples with 100 and 50 copies/mL, respectively.

Conclusions: The performance of most assays met or exceeded their specification on sensitivity. If assays are to be used to analyze sample pools, the sensitivity of the assay and the number of pooled samples must be balanced.

Keywords: PCR; SARS-CoV-2; external quality assessment; limit of detection; nucleic acid test (NAT); pooling.

PubMed Disclaimer

References

    1. Arnaout, R, Lee, RA, Lee, GR, Callahan, C, Cheng, A, Yen, CF, et al.. The limit of detection matters: the case for benchmarking severe acute respiratory syndrome coronavirus 2 testing. Clin Infect Dis 2021;73:e3042–6. https://doi.org/10.1093/cid/ciaa1382.
    1. WHO. Technical specification for selection of essential in vitro diagnostics for SARS-CoV-2, version 14 June 2021. Available from: https://apps.who.int/iris/rest/bitstreams/1351095/retrieve.
    1. Buchta, C, Camp, JV, Jovanovic, J, Radler, U, Puchhammer-Stöckl, E, Benka, B, et al.. A look at the precision, sensitivity and specificity of SARS-CoV-2 RT-PCR assays through a dedicated external quality assessment round. Clin Chem Lab Med 2021;60:e34–7. https://doi.org/10.1515/cclm-2021-1004.
    1. Pum, J. A practical guide to validation and verification of analytical methods in the clinical laboratory. Adv Clin Chem 2019;90:215–81. https://doi.org/10.1016/bs.acc.2019.01.006.
    1. Torres, I, Albert, E, Navarro, D. Pooling of nasopharyngeal swab specimens for SARS-CoV-2 detection by RT-PCR. J Med Virol 2020;92:2306–7. https://doi.org/10.1002/jmv.25971.

LinkOut - more resources